I've never encountered a noise lie that. Does it do it all the time. You could take the air filter loose and run it at idle and see what area it's coming from. Listen through a piece of hose to pin point it.

The sound exactly coming from the Air Filter Box, when I keep my ears closers to that box and I put my hand on it, the sounds come from it. In additional, when I open the Air Filter Box while the engine is running, the same sound/moan keeps increasing.

Today, I have noticed also the sound is not only coming in the Morning or when the car is cold, even when i run on the highway with 50 or 60 mph.

You could try cleaning the throttle body with throttle body cleaner. May be a vacuum leak. Since you just bought it, you never know if someone messed with the throttle stop. Was it doing that when you bought it?

I'm planning to change the IAC, Air Filter, spark plugs and will clean the Throttel Body as suggested. Later on, I will change the COP and will see.

Do you recommend Motorcraft Brand over Ford Genuine Parts? I have checked in the one of the shop and found Motorcraft parts, compare to ford genuine parts the price is less. But what about performance and quality? any thoughts :)

Do you recommend other things to be done apart for cleaning the throttel body and changing other parts?

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